Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L9/00—Rigid pipes
  • F16L9/02—Rigid pipes of metal
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S138/00—Pipes and tubular conduits
  • Y10S138/06—Corrosion
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/0318—Processes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/8593—Systems

Definitions

• the present invention relates to tubes or pipes to be used for water or hot-water supply, and particularly tubes having conspicuously low dissolution of copper or other elements thereof.
• various kinds of tubes or pipes e.g., copper tubes, steel pipes, steel pipes plated with zinc etc. have been used.
• the present invention aims to provide Cu-alloy tubes which greatly contribute to keeping supply water, especially for drinking, highly potable and moreover to enhancing the strength, the workability and productivity thereof.
• the principal object of the present invention is to aim at the provision of such high quality Cu-alloy tubes for the use of water piping and such instruments, to meet this urgent requirement.
• a primary object of this invention is, therefore, to provide an improved tube for drinkable clean water and/or hot-water supply, superior in the dissolution rate of the principal element or elements thereof into either running or stagnant water and thereby superior from the standpoint of sanitation and preservation of water quality.
• Another object of this invention is to provide an improved instrument which comprises a tube or tubes of this invention and may be used for waterworks having the same advantage.
• Still another object of this invention is to provide an improved tube superior in durability, workability, and manufacturing cost saving.
• the essence of this invention for achieving these objects resides in the provision of a copper base alloy tube for water and/or hot-water supply, which alloy is generally classified into two types; (1) first alloy being composed of 0.05-2.8% Mg and the balance Cu and inevitable impurities, (2) second alloy composed of 0.05-2.8% Mg, up to 1% Ca, and the balance Cu and inevitable impurities.
• first alloy being composed of 0.05-2.8% Mg and the balance Cu and inevitable impurities
• second alloy composed of 0.05-2.8% Mg, up to 1% Ca, and the balance Cu and inevitable impurities.
• all percentages indicate the percent by weight.
• the specific ratios of Mg and Ca occupied in the alloys of this invention are very significant and critical as hereinafter described more in detail.
• Table No. 1 shows, as examples, the chemical compositions of the alloys for tubes in accordance with the present invention invention in comparison with that of the conventional and well-known copper tubes for waterworks (JIS H 3603 seamless copper water tube corresponding to ASTM B 88-75 phosphorous deoxidized copper tube).
• Table No. 2 shows examples of test results with respect to the dissolution of copper ions under different temperature conditions and different staying hours.
• Table No. 3 shows examples of test results with respect to the dissolution of copper ions (1) in the case of stagnant hot-water supply over the range of various staying hours and (2) in the case of water once heated and left cooling down naturally, classified by the frequency of the test repetition.
• the essential matter of this invention is to provide a tube made of one of two types of copper base alloys (1) one is a copper base alloy consisting essentially of 0.05-2.8% Mg and the balance is Cu and inevitable impurities, (2) the other is a copper base alloy consisting essentially of 0.05-2.8% Mg, up to 1% Ca and the balance Cu and inevitable impurities.
• Mg as an ingredient of the alloy is surprisingly effective in restraining the dissolution rate of copper ions (cupric ions) into water and also contributive to improvement of strength of the alloy.
• such elements as Si, Ni, Fe, Mn, Ag, Ti, V, Al, Sn, Li, P, Zr, Be, Nb, B, Co, Cr, Na, K, Ta, Te, Mo, Ba, W, Sb, etc, may be present and allowable individually or in combination up to the limit of the solid solubility of each element. Presence of these elements is harmless to the properties of the tubes of this invention; and what is more, such elements as Si, Ni, Fe, Mn, Ag, Ti, and V are contributive to the improvement of the strength, and Al and Li are respectively effective in the formation of a protective skin layer.
• P, Zr, Be, Nb and B are all effective as deoxidizers and contributive to the improvement of castability.
• Zn it is desirable to be limited within 1.0%.
• the tubes are softened in a bright annealing furnace at the temperature of 550°-600° C.
• the dissolution rate of magnesium from the alloy tubes of this invention increases with the increase of Mg added therein.
• the alloy tubes of this invention are, to sum up its features and properties, of high value in respect to not only (a) corrosion resistance, (b) superior workability in piping arrangement, (c) similar easiness of manufacturing as traditional tubes, (d) enough strength, and (e) low manufacturing cost but also in respect to high preservation of water quality because of its dissolution rate of Cu and Mg, the principal elements thereof, into the water and/or hot-water supply including drinking water.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Rigid Pipes And Flexible Pipes (AREA)

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Cited By (7)

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Citations (23)

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• 1974
  • 1974-12-23 JP JP14779174A patent/JPS5344136B2/ja not_active Expired
• 1979
  • 1979-03-26 US US06/024,179 patent/US4337793A/en not_active Expired - Lifetime
  • 1979-03-26 US US06/024,178 patent/US4337785A/en not_active Expired - Lifetime

Patent Citations (23)

Non-Patent Citations (3)

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